of cases so operated on, coitus still continued for
from five to seven days, and in the minority for a longer time. He
therefore concluded, with Goltz, that it is from the swollen testicles,
not from the seminal receptacles, that the impulse first starts. Goltz
himself pointed out that the fact that the removal of the testicles did
not stop coitus by no means proves that it did not begin it, for, when the
central nervous mechanism is once set in action, it can continue even when
the exciting stimulus is removed. By extirpating the testicles some months
before the sexual season he found that no coitus occurred. At the same
time, even in these frogs, a certain degree of sexual inclination and a
certain excitability of the embracing center still persisted, disappearing
when the sexual epoch was over.

According to most recent writers, the seminal vesicles of mammals are
receptacles for their own albuminous secretion, the function of which is
unknown. Steinach could find no spermatozoa in these "seminal" sacs, and
therefore he proposed to use Owen's name of _glandulae vesiculares_. After
extirpation of these vesicular glands in the white rat typical coitus
occurred. But the capacity for _procreation_ was diminished, and
extirpation of both _glandulae vesiculares_ and _glandulae prostaticae_ led
to disappearance of the capacity for procreation. Steinach came to the
conclusion that this is because the secretions of these glands impart
increased vitality to the spermatozoa, and he points out that great
fertility and high development of the accessory sexual glands go together.

Steinach found that, when sexually mature white rats were castrated,
though at first they remained as potent as ever, their potency gradually
declined; sexual excitement, however, and sexual inclination always
persisted. He then proceeded to castrate rats before puberty and
discovered the highly significant fact that in these also a quite
considerable degree of sexual inclination appeared. They followed,
sniffed, and licked the females like ordinary males; and that this was not
a mere indication of curiosity was shown by the fact that they made
attempts at coitus which only differed from those of normal males by the
failure of erection and ejaculation, though, occasionally, there was
imperfect erection. This lasted for a year, and then their sexual
inclinations began to decline, and they showed signs of premature age.
These manifestations of sexual sens